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Silkworm excrement (SE) and silkworm excrement-derived biochar (BC) were applied to atrazine-contaminated soil at the rates of 0% and 0.5% (w/w), respectively. The effect of organic amendments on sorption capacity, microbial biomass carbon, enzyme activity (dehydrogenase, urease and catalase) and bacterial composition in soil were evaluated. Atrazine significantly decreased the microbial activity and diversity in soil. Both SE and BC treatments increased the sorption of atrazine in soil. SE treatment significantly increased the microbial biomass carbon and enzyme activity in contaminated soil. Unlike the addition of silkworm excrement, BC treatment had no significant effect on dehydrogenase activity. Additionally, Illumina-MiSeq sequencing analyses showed that the two organic amendments increased the Shannon index of bacteria. SE treatment improved the relative abundance of Bacteroidetes. BC treatment improved the Proteobacteria in atrazine contaminated soil. [ABSTRACT FROM AUTHOR]

The accumulation of cadmium (Cd) in facility soil is attracting increasing attention. Reductive soil disinfestation (RSD) is an effective soil disinfectionmethod, while also having a certain passivating effect on Cd. The application of organic matter is crucial for the success of RSD, but the reduction efficiencies of different organic materials vary. Here, five treatments, namely untreated soil (CK), bean dregs (BD), peanut dregs (PD), sesame dregs (SD), and apple dregs (AD) were applied, and their performances in Cd immobilization in Cd-contaminated soil were assessed. Changes in soil properties and microbial communities were monitored. The results showed that the overall soil pH following RSD treatment decreased significantly, while organic matter, hydrolyzed nitrogen, available phosphorus, available potassium, exchangeable calcium, and exchangeable magnesium increased significantly. Compared to CK, the exchangeable (EX)-Cd contents after treatments SD and AD significantly decreased by 25.4% and 23.7%, respectively. RSD led to significant changes in the composition of soil microbial communities. SD treatment significantly increased the number of soil fungal operational taxonomic units (OTU), while BD, PD, and SD significantly increased the relative abundances of Bacteroidetes, Chloroflexi, Deinococus Thermus, and Basidiomycota in bacterial communities. The Gemmatimonadetes phylumshowed a highly significant negative correlation with EX-Cd, indicating that it might have a positive effect on the fixation of Cd in polluted soil. SD significantly reduced the Cd content in the above-ground parts of lettuce by 74.76%, and had the least impact on lettuce biomass. It can be inferred that RSD is an ecologically effective method for the remediation of Cd pollution in facility soil by improving soil characteristics and altering microbial community composition to reduce Cd activity. However, further in-depth research is needed to optimize the types and amounts of organic materials applied. [ABSTRACT FROM AUTHOR]

Purpose: At the vicinity of metallurgical and steel activities, notable contamination of Potentially Toxic Elements (PTE) is measured in discrete environmental compartments (soils, biosphere, atmosphere). The main question addressed in this study pertains to the influence of industrial dust fallout on PTE concentrations in soils. The study was conducted near the seaport of Dunkerque, belonging to one of the most industrialised and dust-emitting sites of France. Materials and methods: A composite sample of dust fallout was collected over a 4-month-period in urban areas downwind of nearby industries. SEM-EDS and ICP-AES/MS analyses were conducted on this sample to identify metallurgical particles and highlight the main tracer elements of industrial activities. Then, a comprehensive characterization of soils was conducted to map the spatial distribution of metallic pollution levels in the study area. Nearby soil parameters analysis (grain-size distribution, pH, CEC, SOM, calcium carbonates and water contents), the soil chemical composition was identified using XRF and ICP-AES/MS analyses. Results and discussion: We quantified the proportion of particles of industrial origin in the composite dust sample at 88% of the total fraction, stressing the importance of metallurgical activities near the seaport of Dunkerque. This dust sample shows particularly high enrichment factors (EF) for Cd, Cr, Ni, and Mo with values of 235, 108, 78 and 169 respectively. The use of different pollution assessment indexes evidences that Mo-Cr-Ni associations appear particularly interesting to trace the incorporation of metallurgical sedimentable dusts into soils. Thus, we identified the presence of distinct high-PTE patches related to industrial dust deposition in the studied soils, with a parallel decrease in their quality index (i.e. Mo Geo Accumulation Index indicating moderate to heavy contamination). Conclusions: Our study revealed that the soils located close to the industrial area are the most affected by industrial dust deposition. Several factors explaining the spatial distribution of the soil contamination levels are examined, and it seems that distance from emission sources is not necessarily the most relevant. The study suggests that distribution of plant cover or buildings may act as barriers preventing soils from being exposed to dust deposits. [ABSTRACT FROM AUTHOR]

Hydrocarbon pollution has led to the destruction of farmlands and fishing settlements in the Niger Delta. In this study, DNA metabarcoding was used to investigate bacterial response during the remediation of an artisanal refining site. Total petroleum hydrocarbons reduced from 93,720 mg kg–1 on timepoint zero to 9,029.76 mg kg–1 on day 91. Bacterial species distribution significantly reduced during remediation. The most responsive phyla to the remediation approach were Proteobacteria and Cyanobacteria. Pathways for hydrocarbon degradation were differentially abundant during remediation. Overall, nutrient addition and intermittent tillage improved bacterial energy yield and the degradation of hydrocarbons. [ABSTRACT FROM AUTHOR]

The areal distributions of the soil organochlorine pesticide (OCP) levels were investigated at adjacent and surrounding sites of the obsolete pesticide stockpile warehouse in Kocaeli, Türkiye. OCP levels in soil at neighboring sampling locations (positioned at 0.4 to 3 km from the stockpile) varied from 0.4 to 9 µg/kg and 4.2 to 2226 µg/kg (dry weight) for ΣHCHs and ΣDDXs, respectively. Levels at adjacent locations (positioned within 20 m from the stockpile) were considerably higher, varying from 74 to 39,619 µg/kg and 1592 to 30,419 µg/kg for ΣHCHs and ΣDDXs, respectively. Levels of OCPs dropped abruptly with the horizontal distance from the stockpile and had different transect profiles. The enantiomer fractions (EFs) near the stockpile range from 0.494 to 0.521, 0.454 to 0.515, and 0.483 to 0.533 for α-HCH, o,p′-DDT, and o,p′-DDD, respectively. These near-racemic EFs suggested that observed soil OCP levels were mainly influenced by recent emissions from the stockpile. A comparison of OCP compositions observed in the soil at the present study with the technical HCHs and DDTs revealed that the material in the stockpile primarily contains byproducts that were discarded during DDT and Lindane production at the adjacent plant instead of their technical mixtures. [ABSTRACT FROM AUTHOR]

This study aims to determine the effects of different land management systems on the physical and chemical properties of soil. Soil samples were collected at a depth of 0-30 and 30-60 cm from the greenhouses area and were analyzed in the laboratory using standard protocols. The physical properties) and chemical properties of the soil samples were examined. pH values recorded in the control site ranges from 7.9 to 9.7 indicating that all the soils studied were moderate to strong alkaline. The conductivity values range from 230 μS/cm-8.6 dS/m which indicated that all the soils vary from non-saline to moderately saline. Organic matter ranges from 0.3-1.6%, which indicates that its content is classified from very low to low. Available phosphorus also varies from 0.2-1.3 mg/kg, which indicates a low content of this element. From the study it was concluded that soil properties change through soil management based on the physical and chemical properties of soils through their classification for soil quality and environmental protection. [ABSTRACT FROM AUTHOR]

This study, which considers coal mining sites, aims to solve problems pertaining to the immense permeability, poor stability, and the environmental pollution of soil. In regard to reconstituted soil, the novel "2+1" layered construction technology entails designing a water-resisting layer, a modified layer, and an evaporation inhibition layer on the surface of the gangue hill. This technology, which entails constructing a novel type of reconstituted soil, considered four mechanical and physical soil properties, namely soil particle size, humidity, unit weight, and soil structure grade. The construction of novel reconstituted soils should consider the influence of biological factors and that of an arid environment, as well as the influence of the soil permeability coefficient, water content, density, temperature, and water-soil interaction; simultaneously, it should consider the chemical composition. With respect to the water-resisting layer, we selected loess and feldspathic sandstone that exhibited high clay content, and we utilized a 20 cm design thickness. The modified layer was composed of sandy loess, weathered coal, and feldspathic sandstone. This layer was exhibited a 60 cm design thickness, and it considered the characteristics pertaining to vegetation, soil compactness, and soil chemical composition. The evaporation inhibition layer was designed using materials such as gravel and straw checkerboard. Regional tests indicated that verified the rational robustness of the novel "2+1" reconstituted soil layered construction. The results provide a reference for ensuring the ecological sustainability of coal mining sites that characterize the arid, desert areas of Northwest China. [ABSTRACT FROM AUTHOR]

Remediation of mercury (Hg)-contaminated soil by mycorrhizal technology has drawn increasing attention because of its environmental friendliness. However, the lack of systematic investigations on arbuscular mycorrhizal fungi (AMF) community composition in Hg-polluted soil is an obstacle for AMF biotechnological applications. In this study, the AMF communities within rhizosphere soils from seven sites from three typical Hg mining areas were sequenced using an Illumina MiSeq platform. A total of 297 AMF operational taxonomic units (OTUs) were detected in the Hg mining area, of which Glomeraceae was the dominant family (66.96%, 175 OTUs). AMF diversity was significantly associated with soil total Hg content and water content in the Hg mining area. Soil total Hg showed a negative correlation with AMF richness and diversity. In addition, the soil properties including total nitrogen, available nitrogen, total potassium, total phosphorus, available phosphorus, and pH also affected AMF diversity. Paraglomeraceae was found to be negatively correlated to Hg stress. The wide distribution of Glomeraceae in Hg-contaminated soil makes it a potential candidate for mycorrhizal remediation. [ABSTRACT FROM AUTHOR]

Soil is the mixture of biotic and abiotic substances. The soil can be considered a chief organizing center for land ecosystem. During present situations as well as past years the graph of pollution is rapidly increasing in the world. The land is also polluted with the polluted air and water. The air polluting agents and polluted particles air also make pollution on the soil and land. The water polluting agents either soluble in water or unsoluble in water also create the pollution on the land with mixing in the soil or sand etc. The acid rain and green house gases also effect on the lives of land and quality of soil. [ABSTRACT FROM AUTHOR]

[Display omitted] • Integration of GeoDetector and RF is used to analyze 22 driving factors of soil HMs. • Driving factors have different explanatory powers for soil HMs and interact with each other. • Interaction between geology and anthropogenic is the primary cause of soil HMs contamination. • Use driving factors with strong explanatory power to predict soil HMs distribution. • Explores a new idea for the prediction of soil pollution high-risk areas on a large-scale. The excessive presence of heavy metals (HMs) in soil poses a significant threat to both ecosystems and human health. Consequently, there is a compelling need for quantitative analysis of HMs concentration in soil and the prediction of potential contamination. In this study, 58 surface soil samples were systematically collected from 11 different townships in Luolong County. Using ArcGIS 10.7, the fishing net interpolation resampling was performed to obtain model data. The GeoDetector model was employed to determine the key driving factors and their interrelationships affecting soil composition. Subsequently, influential driving factors with higher explanatory power and employed a Random Forest (RF) model to generate a contamination prediction map. The results revealed that arsenic (As), cadmium (Cd) and lead (Pb) exceeded the risk screening values by 8.62%, 10.34%, and 10.34%, respectively. The GeoDetector model identified factors such as elevation, annual average precipitation, distance to the nearest river, geomorphic type in natural sources, geological type in geological sources, distance from roads, proximity to mining sites, per capita income of inhabitants, total potassium content and organic matter content in anthropogenic sources significantly influencing the spatial distribution of HMs concentration in the soil. The interactions among the primary driving factors increased their explanatory capacity. By using RF model to predict the spatial distribution of the main influencing factors of HMs, it was found that areas with a high probability of As contamination were mainly concentrated in the northern, central and southeast regions of Luolong County. Regions with Cd concentration exceeding the risk screening value were primarily concentrated in the east, northeast and a few northern areas of Luolong County, while the likelihood of Pb contamination was higher in the northern and southwestern regions of Luolong County. This study integrates spatial stratified heterogeneity with the random forest model to mitigate overfitting in the prediction of soil HM contamination, a common issue in traditional machine learning methods. This approach is essential for elucidating the environmental drivers of soil HM pollution, predicting high-risk areas in regions with complex environmental conditions and limited data, and ensuring the safety and stability of agricultural production as well as the well-being of local residents. [ABSTRACT FROM AUTHOR]

[Display omitted] • SOM significantly inhibited TCS and NPS degradation in the Fe2+/PS system. • Molecular properties of the three PPCPs determined their reactivity with oxidants. • SO 4 •− and 1O 2 played major roles in TCS and NPS degradation in different soils. • Soil surface functional groups possibly consumed •OH and 1O 2 , and generated SO 4 •−. • Soil types affected the degradation pathways of TCS and NPS in different soils. Pharmaceuticals and personal care products (PPCPs) are widely used worldwide and cause potential soil pollution. Fe2+-activated persulfate (PS) processes (Fe-PAPs) are promising techniques for soil remediation. However, a knowledge gap exists in the mechanistic insights into the dominant factors affecting the degradation of different PPCPs in varied soil types. This study systematically investigated the roles of soil components and pollutant properties in the degradation of three PPCPs (triclosan (TCS), triclocarban (TCC), and naproxen (NPS)) in the nine soils in the Fe2+/PS system. The degradation efficiencies of TCS and NPS ranged from 10.92 % to 91.62 % and 46.59 % to 99.81 %, respectively, whereas nearly no degradation was observed for TCC. PPCPs with high water solubility, high energies of the highest occupied molecular orbital (E HOMO), low p K a values, low energy gap (ΔE), or low vertical ionization potential (VIP) were more favorable for degradation. XPS analysis suggested that aliphatic carbon (Ali–C–C(H)), ether or alcohol carbon (C–O), and aldehyde or ketonic carbon (C O) on SOM significantly inhibited TCS degradation. The results of ROS quenching experiments showed that SO 4 •− and 1O 2 played major roles in TCS and NPS degradation in the six soils, with the relative contributions ranged from 24.82 % to 99.14 % and 0.15 % to 73.40 %, respectively. The interaction between soil components, active species, and pollutants resulted in the distinct intermediates of TCS and NPS in different soils. Our findings provide in-depth insights into the role of soil composition and pollutant properties on the remediation of PPCP-contaminated soils in Fe-PAPs. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the cytotoxic activity and the chemical composition of the tomato extracts coming from, Pomodoro Giallo and San Marzano Cirio 3, and then to evaluate the potential changes when plants were grown in soils contaminated by cadmium, chromium and lead. Extracts were investigated by UHPLC-HRMS and UV–Vis. Cell viability (CellTiter-Glo Luminescent assay), enzyme aldehyde dehydrogenase activity (ALDEFLOUR Assay), cell cycle progression (Accuri C6 Flow Cytometer), apoptosis and necrosis (Annexin V-FITC assay) were evaluated on two gastric cancer (AGS and NCI-N87) and two colorectal cancer (HT-29 and HCT 116) cell lines. Different content of polyphenol and carotenoid constituents was observed. Extracts from uncontaminated soil induced cytotoxic activity towards all selected cancer cells, while extracts coming from contaminated soils showed the aberrant phenotype increased in colorectal cancer cells. Chloroform extracts exerted the highest cytotoxic activity. AGS and HT-29 were the most sensitive to cell cycle arrest and to apoptosis. No necrotic effect was observed in HCT 116. The contrasting effects on cancer cells were observed based on tomato variety, the extract polarity, heavy metal identity, and tested cell line. The investigation of potential adverse health effects due to Cd in the fruits should be explored. [ABSTRACT FROM AUTHOR]

Soil polluted by oil and its derivatives is a critical environmental issue worldwide that jeopardizes ecological systems and causes geotechnical problems. This review paper focuses on the previous studies concerning the impacts of oil pollution on soil geotechnical properties. To this end, related academic literature on this topic was investigated and discussed. The findings of this study demonstrated that the addition of oil pollution in coarse-grained soils significantly reduces particle surface roughness. On the other hand, in fine-grained soils, it results in flocculation and secondary aggregation of clay particles, less aggregated and loose packing in the soil matrix, the formation of isometric pores, the formation of fissure-like pores, and an increase in mesoporosity. In general, it was found that the geotechnical properties of oil-polluted soils are mostly determined by the physicochemical and/or physical interactions between the soil and contaminant. Additionally, previous research has demonstrated that oil pollutants alter the geotechnical properties of cohesive and non-cohesive soils significantly, including the Atterberg limits, particle-size distribution, compaction behavior, unconfined compressive strength, friction angle, cohesion, hydraulic conductivity, and consolidation characteristics. However, no general pattern could be established for the majority of them. Besides, it was found that the degree of geotechnical property alteration of oil-polluted soil is strongly influenced by the soil type and features, as well as the quantity, type, and chemical composition of oil pollutants. [ABSTRACT FROM AUTHOR]

Field and laboratory investigations were conducted to characterize the composition of petroleum hydrocarbons in oily sludge and the underlying contaminated soils in a decommissioned oilfield waste pit in Kuwait. The results show that the petroleum hydrocarbon composition in the oily sludge and contaminated soils was spatially variable. Highly toxic petroleum hydrocarbon species such as BTEX and PAHs were generally lacking, and both sludge- and soil-borne hydrocarbons were dominated by long-chain petroleum hydrocarbons. The soil contamination depth was generally very shallow although localized deep profiles (>0.5 m) were found. A loose relationship was established between TPH in the sludge and that in the underlying soil. On average, the soil had a greater percentage of shorter-chain hydrocarbon fractions (either aliphatics or aromatics), as compared to the sludge. The environmental risk from the oily sludge and contaminated soils is considered to be relatively low. For cost-effective management of the environmental risk of decommissioning an oilfield waste pit, containment of the sludge and contaminated soils using a soil-capping approach may be sufficient to minimize the possible adverse environmental impacts from the decommissioned waste pit, and this may represent an option that is superior to other costly remediation strategies. [ABSTRACT FROM AUTHOR]

Purpose: Microbial exoenzyme activity (EEA) and stoichiometry (EES) are of great significance to soil health through their influence on carbon (C), nitrogen (N), and phosphorus (P) cycling. However, when agricultural soil is contaminated by cadmium (Cd), the underlying mechanisms and effects on EEA and EES are still poorly understood. Materials and methods: Here, we examine the effect of different remediation treatments (no amendment, 0.3% lime application, and 1.0% biochar application) on EEA and EES and the driving factors in a Cd-contaminated Brassica napus soil. Results and discussion: The activities of a C-acquiring enzyme (β-1,4-glucosidase), N-acquiring enzymes (β-N-acetyl-glucosaminidase, leucine aminopeptidase, urease, and protease), and a P-acquiring enzyme (acid phosphatase), together with related environmental factors (soil pH and different Cd fractions), substrate factors (soil organic C, total N, and P content), and biotic factors (bacterial diversity and community composition) were analyzed. We found that lime and biochar amendments both significantly reduced EEA (normalized by the microbial biomass C), indicating lower microbial investment in exoenzyme production after remediation. Only lime amendment resulted in greater exoenzyme C:P and N:P ratios, and biochar application did not significantly affect EES. Among all the factors, the relative abundance of Acidobacteria and the bacterial Chao index, rather than available Cd content, accounted for the largest variations in soil EEA and EES, respectively. Additionally, the shoot Cd significantly decreased while the N and P content significantly increased after lime and biochar amendments. The higher shoot N content significantly associated with lower EEA and EES, suggesting that the rapeseed might modulate the microbial community and then the function based on nutrient status. Conclusions: Our results suggest that lime and biochar applications in mild Cd-contaminated soil tend to affect extracellular enzymes indirectly by mediating bacterial diversity, which may also be modulated by plant nutrient status. These results will provide useful information for Cd remediation and maintaining the sustainability of soil ecosystem services. [ABSTRACT FROM AUTHOR]

X-ray fluorescence spectrometry (XRF) has long been considered a convenient and powerful method for the determination of trace amounts of chemical elements in various types of natural materials. XRF is rapid, reliable, and non-destructive spectroscopic technique, allows performing a direct analysis of solid samples without pretreatment. For the present report, we take advantage of the multielemental capability of the XRF-technique for the determination of major and trace amounts of rock-forming (Stot, Na2O, MgO, Al2O3, SiO2, P2O5, K2O, CaO, TiO2, MnO, Fe2O3(tot)) and trace (F, V, Cr, Co, Ni, Cu, Zn, Ga, Pb, Rb, Sr, Y, Zr, Nb, Ba, La, Ce, Nd) elements in environmental solid samples. Nowadays, study of the soil cover exposed by human-caused impact is an important aspect in understanding the geochemical processes occurring in it. Study object is the biggest territory of the Baikal region named Olkhon, which is a natural area of preferential protection of federal significance and a part of the Baikal National Park. In this study, we have determined chemical composition of the soil upper horizon (~0–15 cm) of meadow-stepper landscapes of the Baikal region (the Olkhon Island) to reveal their geochemical features and heavy metal pollution level. Three varieties of the steppe soils were distinguished: middle loamy, light loamy and sandy loam. For the first time, the influence of soil granulometric features on the content level of the rock-forming and toxic elements in them has been established. In addition, the primary data relating to the assessment of the soil heavy metal contamination have been presented. [ABSTRACT FROM AUTHOR]

The relevance of the study is due to the fact the high concentration of copper and zinc ions in waste from electroplating industries and their different migration in the environment make these metals sensitive indicators of industrial pollution. The aim of this work is to study the vertical migration of copper and zinc ions from model sulfate copper‐zinc sludge into the horizons of four soil samples. Technogenic pollution with copper and zinc in the "sludge–soil" system is explained by the chemical composition of galvanic sludge, the properties of metals included in it, and the physicochemical properties of soils. An increase in the content of Cu2+ and Zn2+ with depth is recorded in all layers of the studied soils after pollution with maximum accumulation in the upper layer. The index of the pollution concentration of Zn2+ is 8–31 times higher than that of Cu2+. The fixation of Cu2+ and Zn2+ in the upper soil layer and low migration to the lower layers is facilitated by a high sum of exchangeable cations up to 12.8. The values of the factor of element contamination indicate a high risk of contamination of the upper horizons of the studied soils. [ABSTRACT FROM AUTHOR]

Aims: Arsenic is a nonessential element for plants; however, high levels of As can inhibit plant growth. The toxicity of As is influenced mainly by its speciation in soil. The objectives of the present study were to determine the fractional composition of As in soil, its accumulation in plants, and its potentially toxic effects on the morphological, anatomical, and ultrastructural levels. Methods: In a model experiment, barley (Hordeum sativumL.) was planted in Haplic Chernozem spiked with three different concentrations of As (20, 50 and 100 mg/kg). The fraction composition of As in the experimental soil was analysed using a method of sequential fractionation. The phytotoxic effects of As were analysed microscopically at the tissue, cellular, and intracellular levels. Results: Analysis of the fraction composition of As revealed a higher amount of mobile forms of As that contaminated the generative organs of plants. Oxides of Fe, Al, and Mn became the main soil components to retain As when contamination of As increased. Arsenic toxicity inhibited plant growth by affecting morphological parameters (shape, size, and colour). It caused impairment in the root cells and a reduction in the size of the chlorophyllic parenchyma in the leaves. The ultrastructural analysis found changes in the main cellular organelles (chloroplasts, mitochondria, and peroxisomes). Conclusions: The bioconcentration factor (BCF), bioaccumulation factor (BF-soluble), and translocation factor (TF) allowed evaluation of plant protection mechanisms and determination of hazardous concentrations of As in soil. Despite the high buffering capacity of the soil, high As concentration affected morphological and ultrastructural parameters of the H. sativum. [ABSTRACT FROM AUTHOR]

Knowledge of the influence of microplastics on soil microbiome and nutrients is important for understanding the ecological consequences of microplastic pollution in terrestrial ecosystems. In this study, we investigated whether polyvinyl chloride (PVC) microplastic pollution at environmentally relevant concentrations would affect soil bacterial community and available nitrogen/phosphorus content. The results showed that although PVC microplastics at 0.1% and 1% levels did not have a significant effect on overall bacterial community diversity and composition in soil over the course of 35 days, a number of bacterial genera were significantly reduced or enriched by the presence of microplastics. Potentially due to their effect on certain functional groups, microplastics caused a significant change in soil available P content. It is noteworthy that, depending on soil type, pollution level and plasticizer presence, contrasting effects of microplastics may be observed. Further research is definitely warranted to gain a clearer picture of the threats posed by microplastic pollution in soil environments. [ABSTRACT FROM AUTHOR]

Soil microbial communities are affected by environmental factors. Contamination with heavy metals such as cadmium (Cd) can decrease soil microbial species richness and substantially alter soil microbial species composition. Investigations of the microbial communities in Cd-contaminated soils are necessary to obtain data for soil bioremediation efforts. However, depth-associated variations in microbial community composition and structure in Cd-contaminated paddy soils are not well understood. Here, the effects of various degrees of long-term Cd pollution on soil microorganisms were investigated at different soil depths within the plough layer using 16S rRNA gene amplicon sequencing. We found that, in Cd-polluted soils, microbial communities were more similar between the surface soil and the underlying soil. In addition, microbial community richness and/or diversity were significantly reduced in the Cd-polluted underlying soil as compared with the non-polluted underlying soil. However, species richness in the surface layer was significantly greater in the mildly and severely Cd-polluted soils. The soil microbial communities in the same soil layer differed significantly between the non-polluted and polluted soils. Furthermore, Cd contamination affected the microbial communities of different soil layers differently. Soil pH had a synergistic effect on microbial community abundance and composition. The potential functions of the soil microbiota were mainly related to environmental processing, genetic processing, and metabolic pathways. Notably, our identification of the phyla that were differently abundant among sites with different levels of Cd pollution will provide experimental guidance for further explorations of the effects of Cd on soil microbes in natural environments. Our results not only demonstrate that long-term Cd pollution leads to a marked reduction in microbial richness and diversity in the underlying soil layer, but they also help to clarify how long-term heavy metal contamination affects the soil bacterial community. [ABSTRACT FROM AUTHOR]

Pb2+ and Cd2+ are non-biodegradable heavy metal elements with high toxicity. They, even at trace levels, can cause serious damage to the brain, kidneys, blood, nerves, and other organs. Improper human activities have deposited a large amount of Pb2+ and Cd2+ into the soil, such as sewage irrigation, the abuse of chemical fertilizers and pesticides, as well as the excessive discharge of industrial wastes. The heavy metal ions have inevitably been absorbed by crops and then accumulated in animals. After that, these heavy metals can be enriched thousands of times into the human body, ultimately endangering human health, particularly under the biomagnification of food chain. Therefore, rapid, accurate, and reliable detection of Pb2+ and Cd2+ in soil has been highly urgent to control heavy metal pollution for product safety in modern agriculture. One of electrochemical technique, Anodic Stripping Voltammetry (ASV) can be used for on-site and real-time detection of Pb2+ and Cd2+ in soils, indicating high sensitivity, excellent selectivity, convenient operation, equipment portability, and low cost. However, ASV is susceptible to various influencing factors, leading to the decrease in the accuracy of heavy metals detection. The detection performance also varies in the different ASVs. According to the type of voltammetric signal, ASV can be divided into square-wave anodic stripping voltammetry (SWASV), Differential Pulse Anodic Stripping Voltammetry (DPASV), and Linear Anodic Sweep Voltammetry. Among them, SWASV and DPASV are often used to detect Pb2+ and Cd2+ in soils, due to their higher sensitivity and lower detection limit. Voltammetric parameters negatively influence the stripping peak current of Pb2+ and Cd2+, including pulse amplitude, pulse frequency, and potential increment. Furthermore, the voltammetric response of target heavy metals depends seriously on experimental conditions, such as supporting electrolyte type and pH value, deposition potential, as well as deposition time. More importantly, there is the complex composition in soils, including a variety of metal cations, anions, and rich organic matter, but the content of heavy metal ions is very low. Therefore, the voltammetric signal of heavy metals is relatively weak, particularly that easily interfered with by the complex components in soils. In addition, Cu2+ and organic matter are the most common and serious interference factors in soil. In this review, the interference problem of Cu2+ was proposed for an efficient Cu2+ interference suppression. Moreover, a specific mechanism was also addressed to explore the interference of soil humus on the practical application of Pb2+ and Cd2+ detection using ASV. Sensitive material modified-electrodes were selected to obtain high signal-to-noise ratio voltammetric signals in recent years. Although these materials improve the sensitivity, selectivity, and stability of electrodes, the complex composition in soils will interfere with the detection performance of electrodes, and the amount of material modification, where the concentration of sensitive materials will also interfere with the voltammetric signal of target heavy metals. To accurate and reliably detect Pb2+ and Cd2+ in soils using ASV, the following problems must be solved in future research: 1) To propose an efficient suppression of Cu2+ interference. 2) To explore the interference mechanism of soil humus on Pb2+ and Cd2+ detection, aiming to an efficient suppression of interference, and 3) To develop modified materials with high selectivity and stability, thereby to improve the detection performance of electrodes for Pb2+ and Cd2+. Summarily, the working principle of various ASVs was firstly introduced to analyze the influencing factors on Pb2+ and Cd2+ detection using ASV from three aspects of voltammetric parameters, experimental conditions, and soil material composition. Then, the influencing mechanism of each factor was explained to summary the research advances of influence mitigation. Finally, this finding can provide a promising future of interference research during the detection of Pb2+ and Cd2+ in soils using ASV. [ABSTRACT FROM AUTHOR]

To assess the state of plants and their response to changes in soil properties, the elemental composition of leaves of widespread and pollution-tolerant species Betula pubescens Ehrh. and Salix caprea L. has been studied near the nonferrous metallurgy enterprises in the Kola Peninsula. The content of nutrients and heavy metals in the leaves of undergrowth on technogenic barrens and remediation sites differing in remediation technologies has been analyzed. According to the results of leaf diagnostics, both species under barren conditions are characterized by a noticeable deficiency of K, Ca, P, and, especially, Mn and Zn. The leaves of both species accumulate Ni, Cu, Co, As, Cr, Fe, Al, Pb, V, and S. Willow leaves contain more Cd, Co, Cr, Ni, Cu, Al, Fe, As, S, Ca, K and less Mn than birch leaves. Chemophytostabilization has little effect, and the covering of contaminated soils with a constructed fertile layer leads to the enrichment of birch and willow leaves with Ca, K, and P. Under conditions of continuing atmospheric emissions and gradual accumulation of bioavailable heavy metals in soils after the remediation, the accumulation of metals in leaves is largely determined by the distance from the pollution source, reflecting the possibility of both root and foliar uptake. The concentrations of Ni and Cu in leaves in 2018 did not decrease compared to 2011. The low, albeit varying, ratios of the contents of heavy metals in undergrowth leaves and in the soil and weak correlation of heavy metal contents in these media indicated that B. pubescens and S. caprea retain their ability to regulate their chemical composition even under extreme conditions of technogenic barrens. At the same time, supporting the protective capabilities of plants via optimizing mineral nutrition and soil acidity in combination with a reduction in atmospheric pollution is a prerequisite for efficient remediation of technogenic territories in the Far North. [ABSTRACT FROM AUTHOR]

We have compared the impact of heavy metals (HMs: Cu 660 + Zn 1100 + Pb 650 mg/kg) on agrosoddy-podzolic soils (Albic Retisols (Loamic, Aric, Cutanic, Ochric)) of two arable fields (Chashnikovo, Moscow oblast) with different contents of organic carbon (Corg 3.86 and 1.30%) and different fertility levels using indicators of acute and chronic phytotoxicity. At the same level of polymetallic contamination, the responses of test plants to the presence of high concentrations of HMs and potential remediants (lignohumate and biochar) in soils of the same type with different Corg contents noticeably differ with respect to plant growth parameters and metal accumulation in the phytomass. The HMs contamination of low-fertile soil leads to the complete death of plants in the pot experiment, while plants on highly fertile soil continued to develop until flowering with only slight deviations from the control. Experimental data on the contents of total and water-soluble forms of HMs and nutrients in the studied soils are presented. The relationships between the chemical composition of soils and the results of phytotests have been found using the principal component analysis. It is shown that the threefold difference in the content of Corg between the soils of the same texture and acidity (pH) result in significantly different response of test plants to the same concentration of HMs. The necessity of correcting the standards for the permissible concentration of HMs in soils with due account for the Corg content in addition to pH and texture is discussed. [ABSTRACT FROM AUTHOR]

Crude oil contamination is known to cause unwholesome damage to man, his environment comprising of soil, air and water bodies as well as other forms of life. This study determined the effect of crude oil polluted soils on the composition of different microorganisms and plants and the growth of Pleurotus tuberregium. Oil polluted soils in bowls were amended with sawdust from Brachystegia nigerica as substrate. Fruiting bodies and the diameter of the mushroom cap were found to increase with increasing weeks of exposure to oil as against the control which had no fruiting bodies throughout the experiment. Pepperomia pellucida was found to be the predominant weed (n = 20), followed by Asystasia gangetica (n = 11). The bacterial and fungal counts were higher at the oil polluted soil attached to sclerotia than the control. The growth of Pleurotus tuberregium in the polluted soil samples showed its ability to degrade and utilize hydrocarbon as the source of carbon and energy, thereby remediating the contaminated soil environment. This work has shown that the fungus has bioremediation and pollution control capacity. [ABSTRACT FROM AUTHOR]

This paper presents the first tests of Cu (7875 mg/kg), Pb (1414 mg/kg) and Zn (566 mg/kg) removal from contaminated soil with sewage-sludge–derived washing agents (SS_WAs) (dissolved organic matter, DOM; soluble humic-like substances, HLS; soluble humic substances, SHS) and Na2EDTA (as a standard benchmark) in column experiments. Flow rates of 0.5 ml/min and 1 ml/min were used. Using a 1. order kinetic model, the kinetic constant (k), the maximum concentrations of each metal removed (Cmax), and the initial rates of metal removal (r) were established. At both flow rates, stable flow velocity was maintained for approximately eight pore volumes, for flushing times of 8 h (1.0 ml/min) and 16 h (0.5 ml/min). Although the flow rate did not influence k, it influenced Cmax: at 1 ml/min, Cmax values were higher than at 0.5 ml/min. For Cu and Zn, but not Pb, k was about twofold higher with Na2EDTA than with SS_WAs. Although Na2EDTA gave the highest kCu, Cmax,Cu was highest with DOM (Na2EDTA, 66%; DOM 73%). For Pb removal, HLS was the most effective SS_WA (77%; Na2EDTA was 80% effective). kZn was about twofold higher with Na2EDTA than with SS_WAs. Cmax,Zn was highest with HLS. The quick mobilization of Cu, Pb and Zn with most of the WAs corresponded to efficient metal removal from the exchangeable (F1) fraction. [ABSTRACT FROM AUTHOR]

The fact that there are no real borders between the biosphere, atmosphere, lithosphere, and hydrosphere means that environmental pollution monitoring studies should not only include one of the environmental spheres. Thus, integrated environmental pollution assessment studies conducted in the biosphere, lithosphere, and atmosphere promote the "whole system" approach. In this study, the aim was to determine the pollution in the atmosphere, soil, and plants by taking advantage of the high pollution accumulation characteristics of the mosses. Prevailing wind has the potential to distribute pollutants emitted into the air throughout its path. With this regard, soil, mosses, and atmospheric deposition samples were collected in Çanakkale, Turkey, in two seasons. Concentrations of selected elements were measured by Inductively Coupled Plasma-Mass Spectrometry. The enrichment factor of the selected elements in the soil, moss, and deposition samples was calculated. The highest enrichments were found for Lead in atmospheric deposition, Arsenic in soil, and Mercury in moss samples. Cobalt and chromium accumulated more in mosses than in soil. Elevated arsenic levels found in the samples can pose a great risk for public health and agriculture. The study result showed that the elemental composition of the samples was influenced by the enhanced air plume dispersion of anthropogenic pollution sources along the Northeast-Southwest directions due to wind characteristics in the province. As expected, strong correlations were found among the moss, soil, and atmospheric deposition samples indicating the vital interactions between the environmental components. [ABSTRACT FROM AUTHOR]

Background and aims: Algae and Cyanobacteria species that grow in contaminated sites can accumulate high concentrations of heavy metals. In this work it was proposed to a) characterize the community of algae and Cyanobacteria and b) evaluate the effect of lead (Pb) on the composition of algae present in the rhizosphere of plants capable to accumulate Pb in Córdoba province. M&M: Soil samples were taken from the rhizosphere of Sorghum halepense, Bidens pilosa and Tagetes minuta at sites with different levels of Pb. In the laboratory, the soil was sown in capsules with sterilized Watanabe medium. The cultures grew 9 weeks. The algae and Cyanobacteria were identified over the time and the final relative frequency analyzed. Results: In contaminated soils, 24 species of Cyanobacteria, Chloroplastida and Xanthophyceae were identified. The heterocytous cyanobacteria Cylindrospermum muscicola, Nostoc commune and Calothrix clavata registered a relative mean frequency (between 21 and 60%). Trebouxia parmeliae (Chloroplastida) and Vaucheria sp. (Xanthophyceae) were present in soils with the highest level of Pb. Most of the species were concentrated in the lowest levels of Pb. Conclusions: A negative effect of Pb on the species richness of algae and Cyanobacteria was observed in the rhizosphere of the evaluated plants. Based on the composition of the community of algae and Cyanobacteria in the soil, two groups are determined and could be considered tolerant and non-tolerant communities of Pb contamination. [ABSTRACT FROM AUTHOR]

Hexavalent chromium [Cr(VI)]-contaminated soils have introduced a serious problem in China. Cr(VI) is hazardous to both the environment and public health and may degrade the engineering properties of soils. Accordingly, the effects of Cr(VI) on the physicochemical, mechanical, and microstructure properties of Chinese clay were investigated in this study. Results show that Cr(VI) had a considerable negative effect on the physicochemical, mechanical, and microstructure properties of soil. Specifically, Cr(VI) changed the physicochemical properties and degraded the mechanical properties of soil, led to the aggregation of soil particles, and created a large void space. Cr(VI) also changed the mineral composition of the soil and converted clay minerals into calcite. The changes in the microstructure and mineral composition of the soil were the primary reasons for the differences in the engineering properties of Cr(VI)-contaminated soil. [ABSTRACT FROM AUTHOR]

Purpose: The application of biochar to contaminated soil is an effective strategy to enhance soil remediation by promoting microbial activity. However, the insufficient bioavailability of petroleum in crude oil-contaminated soil limits its application in contaminated soil. Biosurfactant could improve the remediation efficiency of contaminated soil by improving the bioavailability of petroleum in crude oil-contaminated soil. The combination of rhamnolipid and biochar was used to improve the bioremediation efficiency in bioremediation of oil-contaminated soil. Materials and methods: Here, three types of biomass were applied to produce biochar including rice husk (BC), sewage sludge (SC), and petroleum coke (PC). Rhamnolipid was used to modify biochar for assessing their effect in bioremediation of oil-contaminated soil. The rhamnolipid-modified biochar was added to oil-contaminated soil with loading rate of 2% (wt/wt) for a 3-month experiment. Soil properties, greenhouse gas (GHG) emission, and microbial community compositions were characterized. Results and discussion: The application of rhamnolipid-modified biochar exhibited better performance regarding the degradation of petroleum hydrocarbons, diversity, and abundance of microbial communities and degradation of n-alkanes and PAHs than pristine biochar. Besides, the application of biochar played an important role in the bioavailability of indigenous microbial communities for biodegrading of short-chain hydrocarbon. Meanwhile, the biochar amendments increased the emission of CO2 and CH4, while reduced the emission of N2O. Conclusion: The application of rhamnolipid-modified biochar could improve the diversity and abundance of microbial communities and then promote the degradation of n-alkanes and PAHs, providing an effective approach for bioremediation of crude oil-contaminated soil. [ABSTRACT FROM AUTHOR]

Research data on the isotopic composition of carbon in soil lipids in the Zhirnovskoe and Bakhmet'evskoe oil and gas fields in the Medveditsa River basin, Volgograd oblast, Russia, are analyzed. Oil and atmospheric soil pollution is recorded. The variations in the isotopic composition are determined by both anthropogenic factors and the diversity of natural conditions. The isotopic composition of carbon in the lipids of the interfluvial soils (chernozems) is heavier (–26.9 to –29.2‰) than that in the alluvial soils (–29.4 to –31.3‰) because of the differences in the moistening and temperature conditions. Oil pollution appears as a lighter isotopic composition (–29.3 to –29.8‰) since oil isotopic composition is in general somewhat lighter (–28.4 to –30.6‰) as compared with unpolluted soils. Urban and transport infrastructure makes the isotopic composition of atmospheric CO2 lighter, thereby influencing the δ13С values of plants and soils. [ABSTRACT FROM AUTHOR]

The article is devoted to the pollution problems and the identification of the main sources of pollution of Boyuk Shor lake of the Absheron Peninsula under the ever-increasing rate of industrial development and urbanization. The purpose of the research was to determine the current ecological state of Boyuk Shor lake and adjacent territories. For this purpose, in June–August 2018, 36 samples were taken for analysis from water, bottom sediments of the lake, and soils of adjacent territories. The laboratory analysis revealed a high content of total hydrocarbons, toxic metals (Cd, Co, Hg, Cu), suspended solids, and other pollutants in the lake water samples. Quantitative and qualitative indicators of the lake are presented. The number of suspended particles in water samples was found to be more than 27–250 times higher than the maximum permissible concentration, and the amount of Hg is 180–286 times, Cd is 1–3.3 times, Cu is 1.7–4.8 times, and Co is 1.5–2.4 times higher than MPC. The heavy metal pollution of the soil and the taxonomic composition of the mesofauna of the surrounding area of Boyuk Shor lake were also studied. It was found that the composition of the group of soil invertebrates is very scarce, consisting only of insects (Arthropoda) (85.7%) and mollusks (Mollusca) (14.3%). The research results showed that the long-term negative impact has led to a violation of the ecological balance of the lake; it has lost its natural qualities, has become unsuitable for the flora and fauna of the lake and the surrounding area, and needs thorough cleaning and restoration. [ABSTRACT FROM AUTHOR]

Fungi play an important role in bioremediation of contaminated soil. However, the diversity of fungal populations in four mine-contaminated soils located in Hechi City has remained unexplored. In this study, high-throughput sequencing of ITS was performed to investigate the diversity and abundance of fungal communities in four mine-contaminated soils in Hechi city. Phylogenetic taxonomy showed that the fungal communities included five phyla. Ascomycota and Basidiomycota were the most abundant phyla in four samples. The most abundant fungi included Agaricomycetes, Nectriaceae, Eurotiomycetes, Mortierellaceae, Incertae sedis, Trichocomaceae, Sordariomycetes, and Fusarium. Various fungi with the potential of bioremediation and industrial application were discussed. The results of fungal composition will provide a clue for isolation of new fungi with the potential of bioremediation and industrial application. Furthermore, this study will lay a good foundation for modifying the indigenous fungi by genetic engineering in the future. [ABSTRACT FROM AUTHOR]

This study aims to better understand the relationship between the response to acid mine drainage (AMD) stress of tolerant plants and changes in root-related bacterial communities. In this study, reed stems were planted in AMD-polluted and unpolluted soils, and high-throughput sequencing was conducted to analyze the bacterial community composition in the soil, rhizosphere, rhizoplane and endosphere. The results showed that the effect of AMD pollution on root-associated bacterial communities was greater than that of rhizo-compartments. Proteobacteria were dominant across the rhizo-compartments between treatments. The microbiomes of unpolluted treatments were enriched by Alphaproteobacteria and Betaproteobacteria and depleted in Gammaproteobacteria ranging from the rhizoplane into the endosphere. However, the opposite trend was observed in the AMD pollution treatment, namely, Gammaproteobacteria were enriched, and Alphaproteobacteria and Deltaproteobacteria were mostly depleted. In addition, endophytic microbiomes were dominated by Comamonadaceae and Rhodocyclaceae in the unpolluted treatment and by Enterobacteriaceae in the AMD-polluted soils. PICRUSt showed that functional categories associated with membrane transport, metabolism and cellular processes and signaling processes were overrepresented in the endosphere of the AMD-polluted treatment. In conclusion, our study reveals significant variation in bacterial communities colonizing rhizo-compartments in two soils, indicating that plants can recruit functional bacteria to the roots in response to AMD pollution. [ABSTRACT FROM AUTHOR]

The environment in Kuwait had suffered a massive damage by the Iraqi troops during the 1990-1991 military invasion. 734 oil wells were damaged and burned causing huge amount of oil spills on the soil surface and subsurface. Most of the soil around the oil fields was affected by hazardous contamination. This study aims to measure the extent of contaminated soil and to determine the contaminant composition, then we choose a suitable remediation action for rehabilitation of Kuwait’s desert environment and ecosystem. Site soil samples taken from five well heads located in Burgan’s field were investigated to measure the depth of the contaminated soil and its composition. The results showed that the contaminated soil was identified, wellhead number three had the deepest contamination of 4.3 meters, and the shallowest depth of 1.2 meter was found at the wellhead pit number one. The number of petroleum hydrocarbons resided in the soil can cause a serious health risk. The necessary remediation actions were made using different quantities and mixing of nutrients. Furthermore, epidemiology studies are needed to monitor the long-term positive impacts of the remediation actions for the pollutants on the ecology, environment, and human health. [ABSTRACT FROM AUTHOR]

Chile is a well-developed agricultural country, which is faced with the problem of agricultural soil contamination with metals, such as Cu, Cd, Pb and Zn, and metalloids (As). These elements can be retained by soils through different mechanisms, i.e., complex-forming with organic matter or occlusion within organic matter. That is why studying soil contamination should also be accompanied by detailed investigations of the soil organic matter composition. Soil organic matter is crucial for plant growth since its decomposition releases nitrogen, phosphorus and other nutrients available for the plants. 13C nuclear magnetic resonance spectroscopy, providing crucial data on carbon functional structures diversity, can also be used to study changes in the soil organic matter (SOM) during decomposition and humification. This study is aimed at investigating the molecular composition of the soil organic matter in the agricultural soils of urbanised areas of central Chile using 13C nuclear magnetic resonance (NMR) spectroscopy. The studied soils were characterised by almost neutral pH values and organic carbon contents from 1.7% to 5.2%. The results showed that soils with an increased content of the total organic matter demonstrated an increased portion of aromaticity and a decreased portion of aliphaticity. Most of the investigated humic acids show the highest peaks centred at 125 ppm, which can be tentatively assigned to aromatic alkene structures. The relatively high stabilisation rate of the organic matter in the studied soils can be explained by the mineralisation of its peripheral part, which, in turn, is explained by the decreasing C/N ratio values. The humic substances of the studied agricultural soils of central Chile showed a high average content of aromatic carbon, which is also typical for subboreal soils. [ABSTRACT FROM AUTHOR]

Crude oil is a serious soil pollutant, requiring large-scale remediation efforts. Bacterial consortia in combination with rhamnolipids can be an effective bioremediation method. However, the underlying mechanisms and associated changes in soil bacterial composition remain uncharacterized. Therefore, this study sought to evaluate the effectiveness of rhamnolipids in petroleum hydrocarbon removal, and the associated bacterial community dynamics during bioremediation of petroleum-contaminated soils. Contaminated soils were subjected to natural attenuation, bioremediation with rhamnolipids, bioremediation with bacterial consortia, or bioremediation with bacterial consortia supplemented with rhamnolipids (BMR). High-throughput sequencing of bacterial sample partial 16S rRNA sequences was performed. Additionally, the n-alkanes and aromatic fractions were analyzed by gas chromatography-mass spectroscopy. The results showed that rhamnolipid supplementation increased the rate and extent of total petroleum hydrocarbon biodegradation to a maximum of 81% within 35 days. Further, phylogenetic analysis revealed that the bacterial community was composed of 14 phylotypes (similarity level = 97%). Actinobacteria and Proteobacteria were the two core phyla in all samples, accounting for 63–89%, but Proteobacteria was the most dominant phylum in the BMR sample (~ 53%). Among the top 20 genera, Pseudomonas, Pseudoxanthomonas, Cavicella, Mycobacterium, Rhizobium, and Acinetobacter were more abundant in BMR samples compared to other samples. Predicted functional profiles revealed that rhamnolipid addition also induced changes in gene abundance related to hydrocarbon metabolic pathways. This study provided comprehensive insights into the synergistic effect of rhamnolipids and bacterial consortia for altering bacterial populations and specific functional traits, which may serve to improve bacteria-mediated petroleum hydrocarbon biodegradation in contaminated soils. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to explore the effects of antimony (Sb) on the nutrient composition of green leafy vegetables. Materials and methods: Red beets (Beta vulgaris L.), mallow (Malva sinensis Cavan.), and Chinese cabbage (Brassicacampestris L.) were planted by pouring antimony solution in flowerpot, then the protein content of plants and the changes of seven nutrient elements such as Ca, Mg, Fe, Mn, Zn, Cu, and I under Sb stress were studied. Results and discussion: The results showed that the red beet had the highest protein content when the concentration was 20 mg L−1, which was 0.2856 gprot L−1. With an increase in the antimony concentration, the protein content decreased gradually, and the protein content of mallow and Chinese cabbage did not change significantly. For nutrient elements, except for Ca and I, other nutrients in red beets increased with the increase in antimony concentration, and Mn and Zn contents in mallow were reduced to the lowest when Sb was treated with 100 mg L−1, while content of I element was the highest at 100 mg·L−1, and the content of nutrients in Chinese cabbage changed in a small range. Conclusions: The research showed that the antimony pollution had a great influence on the protein content of red beet. The nutrient content of mallow was fluctuated greatly when Sb was treated with 100 mg L−1. The content of Mn, Zn, and Cu in Chinese cabbage almost did not change due to the antimony concentration. [ABSTRACT FROM AUTHOR]

Coal mining and related industries each leave their characteristic "metal fingerprint" in the surrounding soils. Although geochemical investigations of such soils most often indicate heavy contamination with certain metals and bioassays point to their cytotoxic and genotoxic effects, the majority of studies are based on only one of the mentioned approaches. Here, the presented study investigated the effect of coal mining activities and related industry on surrounding soils by means of both geochemical and biological tools. The multielement composition of soils and associated eluates were used for the assessment of soil contamination level and the element bioavailable fractions, respectively. For cytotoxicity and genotoxicity evaluation, shallot (Allium ascalonicum L.) roots were exposed to selected soil eluates. Root growth, frequency of mitosis, mitotic and chromosomal abnormalities in root meristem cells, level of lipid peroxidation, and DNA damage evaluated by a comet assay were scored as toxicity endpoints. The results point to significant differences in the composition of collected soils and a variety of factors that contribute not only to their total metal load but also to the observed cytotoxic and genotoxic effects; all of which emphasize the necessity of a multidisciplinary approach in assessing the impact of anthropogenic activities on the environment, especially in historical mining areas. [ABSTRACT FROM AUTHOR]

Purpose: To compare Cd removal from different soils with three washing agents recovered from sewage sludge (dissolved organic matter (DOM), soluble humic-like substances (HLS), soluble humic substances (SHS)). Also, to investigate how washing with these agents changes soil organic-matter composition (OM). Materials and methods: Sandy clay loam (S1) and clay (S2) highly contaminated with Cd (300 mg kg−1) were washed with DOM, HLS, or SHS solutions at various pHs, and with various washing times and washing modes (single or double). Cd distribution and OM composition were determined (including content of humic substances (HS), fulvic fraction (FF), labile humic acids (L-HA), and stable humic acids (S-HA)). Results and discussion: Cd removal proceeded with pseudo-second-order kinetics. Equilibrium was reached in 30 min (S1) and 60 min (S2). DOM, HLS, and SHS removed 75–82% of Cd from S1, and 80–87% from S2. The most mobile fraction of Cd was removed after one wash. S2 retained more OM, including HS, than S1. Although washing did not change the HA/FF ratio in most variants, washing with DOM and HLS increased the percentage of L-HA in both soils. Washing with SHS increased S-HA content in both soils, but the percent content of S-HA was similar to that in the unwashed soil. Conclusions: DOM, HLS, and SHS derived from sewage sludge can effectively remediate clay and sandy clay soils highly contaminated with Cd. Washing with an SHS solution can increase the content of the most stable carbon forms (HA), which is beneficial for carbon sequestration in remediated soils. [ABSTRACT FROM AUTHOR]

The concept of the study resulted from the lack of accurate data on the toxicity of bisphenol F (BPF) coinciding with the need for immediate changes in the global economic policy eliminating the effects of environmental contamination with bisphenol A (BPA). The aim of the experiment was to determine the scale of the previously unstudied inhibitory effect of BPF on soil biochemical activity. To this end, in a soil subjected to increasing BPF pressure at three contamination levels of 0, 5, 50 and 500 mg BPF kg−1 DM, responses of soil enzymes, dehydrogenases, catalase, urease, acid phosphatase, alkaline phosphatase, arylsulphatase and β-glucosidase, were examined. Moreover, the study suggested a potentially effective way of biostimulating the soil by means of bioaugmentation with a consortium of four bacterial species: Pseudomonas umsongensis, Bacillus mycoides, Bacillus weihenstephanensis and Bacillus subtilis, and the following fungal species: Mucor circinelloides, Penicillium daleae, Penicillium chrysogenum and Aspergillus niger. It was found that BPF was a controversial BPA analogue due to the fact that it contributed to the inhibition of all the enzyme activities. Dehydrogenases proved to be the most sensitive to bisphenol contamination of the soil. The addition of 5 mg BPF kg−1 DM of soil triggered an escalation of the inhibition comparable to that for the other enzymes only after exposing them to the effects of 50 and 500 mg BPF kg−1 DM of soil. Moreover, BPF generated low activity of urease, acid phosphatase, alkaline phosphatase and β-glucosidase. Bacterial inoculum increased the activity of urease, β-glucosidase, catalase and alkaline phosphatase. Seventy-six percent of BPF underwent biodegradation during the 5 days of the study. [ABSTRACT FROM AUTHOR]

Global efforts of forestation and reutilization of barren lands to mitigate climate change have increased in last decade. Brownfields are non-utilizable barren lands due to the presence or potential presence of hazardous substance, pollutant, or contaminant. In present study, brownfield of Chak Naurang, Punjab, Pakistan contaminated with petroleum hydrocarbon was analyzed in order to evaluate the possibility of bioremediation. Physicochemical analysis of composite soil sample demonstrated that contaminated soil was slightly alkaline clay-loam with TPH of 22.2 g/kg. The concentration of nitrogen, phosphorus and potassium was found to be quite low i.e. 644 mg/kg, 12.46 mg/kg and, 20 mg/kg, respectively. Electrical conductivity (E.C) i.e., 4.3 dS/m and 18% water content showed the deteriorated condition of affected soil. The crude oil degrading and biosurfactants producing microorganisms were isolated from the contaminated soil using soil enrichment technique. The isolated microorganisms were tested for biosurfactants production on the basis of qualitative and quantitative assays. Our results showed that efficient biosurfactants producing microorganisms belong to the genera of Pseudomonas, Bacillus, Paenibacillus, Achromobacter, Meyerozyma and Aspergillus. Statistical analyses exhibited significant differences (p<0.05) amongst the biosurfactants production capabilities of the characterized strains. These findings revealed that contamination of petroleum hydrocarbons has adversely effected soil composition and agriculture properties. The affected soil harbors diverse microbial communities that can produce biosurfactants and use crude oil as sole carbon substrate. Moreover, nutrients amendments could be an effective strategy to stimulate bioremediation process and for improving soil productivity. [ABSTRACT FROM AUTHOR]

Soils from the old Mortórios uranium mine area were studied to look for contamination, as they are close to two villages, up to 3 km away, and used for agriculture. They are mainly contaminated in U and As and constitute an ecological threat. This study attempts to outline the degree to which soils have been affected by the old mining activities through the computation of significant hot clusters, Traditional geostatistical approaches commonly use raw data (concentrations) accepting that the analyzed elements represent the soil's entirety. However, in geochemical studies these elements are just a fraction of the total soil composition. Thus, considering compositional data is pivotal. The spatial characterization, considering raw and compositional data together, allowed a broad discussion about not only the concentrations' spatial distribution, but also a better understanding on the possibility of trends of "relative enrichment" and, furthermore an insight in U and As fate. The highest proportions (compositional data) on U (up to 33%), As (up to 35%) and Th (up to 13%) are reached in the south-southeast segment. However, the highest concentrations (raw data) occur in north and northwest of the studied area, pointing out to a "relative enrichment" toward the south-southeast zone. The Mondego Sul area is mainly contaminated in U and As, but also in Co, Cu, Pb and Sb. The Mortórios area is less contaminated than the Mondego Sul area. [ABSTRACT FROM AUTHOR]

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The interaction of plants and root-associated bacteria encourage the removal of soil contaminants. Engineers and scientists have looked at this phenomenon as a possible means of soil treatment (rhizodegradation). In this study, root-associated bacteria were isolated and selected for growth on a model soil contaminant: polycyclic aromatic hydrocarbons. Isolates were compared genetically to see how plant–bacteria interactions change with soil contamination levels. Characterization of root-associated bacteria was performed using REP-PCR genetic fingerprinting and 16s rRNA gene alignments for identification. Genomic fingerprinting indicated that the composition of PAH-metabolizing bacteria ("guild") was similar among plant species at each treatment level. However, guild composition changed with contamination level and differed from that of bulk soils, suggesting a common rhizosphere effect among plant species related to PAH contamination. PAH-metabolizing bacteria were identified through 16s rRNA gene alignment as members of the α-, β-, and γ-proteobacteria, Actinobacteria, and Bacilli classes. Burkholderia and Pseudomonas spp. were the only genera of bacteria isolated from all plant types in uncontaminated controls. Bacterial species found at the highest treatment included Achromobacter xylosoxidans, Rhodococcus spp., members of the Microbacteriae, Stenotrophomonas rhizophilia, as well as other members of the alpha-proteobacteria. Given their ability to grow on PAHs and inhabit highly contaminated rhizospheres, these bacteria appear good candidates for the promotion of rhizodegradation. [ABSTRACT FROM AUTHOR]

• Gulf war spilled oil was significantly affected by vaporization, due to the high surface temperatures in the desert. • Comparison with data from other oceanic oil spills showed that less significant degradation occurred in Gulf war soil samples. • Chemical compositions differ between contaminated soils at different depths from the surface. In this study, molecular-level chemical compositions of soils contaminated by oil spilled during the Gulf War were studied. Two soil samples, respectively collected at 0.1 m and between 0.5 and 1 m below the surface from an oil spill site, were extracted with organic solvents and water. The extracts were analyzed via ultrahigh resolution FT-ICR and two-dimensional gas chromatography/high resolution mass spectrometry. The data showed that the spilled oil was significantly affected by vaporization due to high surface temperatures in the desert. The data obtained with (+) atmospheric pressure photo ionization (APPI) and (-) electrospray ionization (ESI) coupled with ultrahigh resolution–mass spectrometry (UHR-MS) indicated that the degradation of aromatic compounds and increase in oxygen-containing classes occurred in the following order: surface soil > below surface soil > crude oil. The oxygenated compounds were confirmed by principal component analysis. The score and loading plots of O x and SO x showed that they were the major contributors to differentiate the samples. However, a comparison with previously reported oceanic oil spills showed that less significant degradation occurred even after almost 30 years. Our data can provide an information basis for designing a strategy for clean-up and restoration efforts of Gulf War oil spills. [ABSTRACT FROM AUTHOR]

Abstract In Bangladesh, India, and Pakistan the ship breaking (SB) sector dismantles end-of-life ships on open beaches, exposing the environment to the resulting pollution, especially the soil and water. Because SB occurs in the vicinity of other poorly-regulated activities in industrial zones (IZ) in these countries, there is some ambiguity concerning the relative roles played by SB and IZ in the accumulation of hazardous materials in the soil. In the absence of comparative studies, this study investigated the relative levels of soil contamination due to SB or IZ in the same geographic region by taking soil samples from SB and unrelated IZs in Chittagong, Bangladesh. The technogenic input of sixty-four chemical elements into the soil at the SB or IZ were compared with off-site reference values or the natural content of these elements in the Earth's crust and surface. The magnitude of soil contamination by ecotoxic elements, the corresponding bioavailability, and the ecological risks were assessed based on the regulatory reference values (RRVs) and with other approaches using data aggregation. Among the different potentially toxic elements, Cr, Cu, Ni, Pb, and Zn were found to be above the maximum allowable concentration (p < 0.05) in both SB and IZ. Moderate-to-high soil contamination from SB and moderate-to-considerable soil contamination in the IZ were observed. However, the element-bioavailability as ascertained via solid-phase speciation or weak-acid induced leaching, and the evaluation of associated ecological risk both indicated a low hazard quotient for soils from both SB and IZ. The outcome of the current research marked both SB and IZ soils as contaminated but not polluted, yet remediation is suggested. The level of contamination in SB soils was relatively higher than that of IZ. The comparative results presented in this study for the first time will hopefully be useful as a reference for future ecological and geochemical studies concerning the environmental contamination associated with both ship recycling on open beaches and other typical industrial activities. Highlights • Impact of open-beach ship-breaking or typical industrial activities on soils. • Study of technogenic inputs of sixty-four chemical elements in soils. • Ship-breaking induces higher element accumulation in soils than typical industries. • Extent of soil contamination due to the ecotoxic element accumulation was assessed. • Bioavailability and the ecological risks thereof have been evaluated. [ABSTRACT FROM AUTHOR]

Abstract Micro-/nano-hydroxyapatite (MHA/NHA) has been used to reduce the concentration of available heavy metals and increase soil pH in the remediation of heavy metal-contaminated soils. However, little is known about the effects of MHA and NHA on soil fungal communities and function. In this study, fungal community composition was characterized from copper-contaminated soils amended with MHA, NHA and three other classic amendments combined with Elsholtzia splendens during a 3-year immobilization experiment. High-throughput sequencing results showed that applications of MHA increased the richness and diversity of the fungal community, which was opposite the results of NHA. SIMPER analysis indicated that both the relative abundance of fungi associated with biosorption and plant growth promotion increased, whereas the relative abundance of fungi related to bioleaching and potential pathogens decreased after applying MHA. Redundancy (RDA) analysis revealed that the soil pH was a crucial environmental factor in the succession of fungal communities. In addition, the results of functional prediction via FUNGuild suggested that the application of MHA had the potential to reduce the risk of pathogens infecting animals and plants in the soil but that NHA had some environmental risks. Overall, fungal community showed a synergistic effect of immobilization with the test amendments, and MHA was better for the remediation of heavy metal-contaminated soils than the other test amendments. Highlights • Fungal community structure significantly varied with the application of MHA/NHA combined with phytoremediation. • The applications of MHA increased the richness and diversity of the fungal community, which was opposite the results of NHA. • The relative abundance of fungi associated with heavy metal-leaching decreased by application of MHA. • The application of MHA had the potential to reduce the risk of pathogens in the soil but that NHA had some environmental risks. [ABSTRACT FROM AUTHOR]

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Abstract Food security is a high-priority issue for sustainable global development both quantitatively and qualitatively. In recent decades, adverse effects of unexpected contaminants on crop quality have threatened both food security and human health. Heavy metals and metalloids (e.g., Hg, As, Pb, Cd, and Cr) can disturb human metabolomics, contributing to morbidity and even mortality. Therefore, this review focuses on and describes heavy metal contamination in soil–food crop subsystems with respect to human health risks. It also explores the possible geographical pathways of heavy metals in such subsystems. In-depth discussion is further offered on physiological/molecular translocation mechanisms involved in the uptake of metallic contaminants inside food crops. Finally, management strategies are proposed to regain sustainability in soil–food subsystems. Highlights • Heavy metal pollution has perturbed the environment to pose serious health hazards. • Therefore, the diverse and emerging issues of food security have become a global concern. • A better understanding on the soil-food crop transfer mechanisms is prerequisite for remediation. • This review provides a general view on the global geographical pattern of heavy metal sources. • The review discusses state-of-the-art remediation approaches to manage soil metal pollution. [ABSTRACT FROM AUTHOR]